Quantcast
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Please explain this ballistics plot to me

Discussion in 'Rifle Country' started by wacki, Oct 5, 2013.

Thread Status:
Not open for further replies.
  1. wacki

    wacki Member

    Joined:
    Sep 16, 2006
    Messages:
    1,693
    Location:
    Reminiscing the Rockies
    I don't understand the combat divergence. Why is a 20" drop OK but 30" means "combat divergence"? To me it's just a simple

    20" = aim for the head, hit the belly.
    30" = aim just above the head, hit the belly

    [​IMG]
     
    Last edited: Oct 5, 2013
  2. rcmodel

    rcmodel Member in memoriam

    Joined:
    Sep 17, 2007
    Messages:
    59,082
    Location:
    Eastern KS
    Looks to me like a chart some Dumas was trying to use to prove the 6.5 Grendal is a better round then the 7.62 NATO.

    He still has some more cyphering to do to prove that!!

    rc
     
  3. wacki

    wacki Member

    Joined:
    Sep 16, 2006
    Messages:
    1,693
    Location:
    Reminiscing the Rockies
    Just found the original post. I found the image on arfcom via a random google image search.
     
  4. Inebriated

    Inebriated Member

    Joined:
    Mar 25, 2011
    Messages:
    3,682
    Location:
    NC
    I'm going to make two assumptions, that the graph is mainly concerned about:
    1) Precision rifles, with precision optics (referencing the M14 in the post on TFL).
    2) Killing living things, not just putting holes in paper (referencing the hunting and combat divergence).

    So it seems that we're talking about the M14 in a designated marksman role... For that, energy transfer means a lot more than a slightly-flatter drop. I'll take .308 all day, every day.

    EDIT - and looking at Hornady's factory loads, the 123gr AMAX 6.5 Grendel has 51" drop, and 881 ft./lbs. at 500 yards. The 178gr BTHP .308 has 44" drop, and 1554 ft./lbs. at 500 yards. Both reportedly from 24" barrels. So at least with those two, the .308 has the edge in every category, other than recoil
     
  5. gotigers

    gotigers Member

    Joined:
    Sep 1, 2009
    Messages:
    1,424
    I agree the .308 is a better choice overall. A little off topic, but if you want to get the most out of an AR15, the 6.5 grendel will fit in an AR15, but you would need an AR10 for the .308. Just a thought.
     
  6. Uncle Mike

    Uncle Mike Member

    Joined:
    Nov 5, 2008
    Messages:
    3,129
    Location:
    never never land...never land here!
    Oh yea, and this just goes on, and on and on....

    The Grendle is a fine cartridge, but better than the 7.62x51...no!:banghead:
     
Thread Status:
Not open for further replies.

Share This Page